The present invention relates to an indexable insert for grooving operations, the basic form of which is triangular and which incorporates a top surface, a plane parallel bottom surface and a number of edge surfaces connecting the top and bottom surfaces. Each corner position of the insert has an extension carrying a cutting edge. Those edges that extend towards the cutting edge of the extension converge towards the edge. The extension could be symmetrical or unsymmetrical in its shape.
Available triangular indexable inserts for grooving have a shape that demands a relatively large amount of cemented carbide compared to the useful cutting edge length. This carbide material is expensive and it is therefore of economic advantage to try to reduce the material necessary for each useful cutting edge. It is also desirable to be able to use inserts of such triangular shape so that they match the standard type holders for polygonal indexable inserts and that such inserts have a shape that enables their usage together with other inserts.
Therefore, one object of the present invention is to shape an indexable insert such that a relatively limited mount of hard material is required and at the same time to provide an insert that fits into a standard type toolholder.
It is another object of the present invention to provide an insert such that it becomes suitable for grooving in a holder which also carries an insert for cut-off in a direction mainly perpendicular from the grooving direction of the indexable insert according to the present invention.